The use of thrust bearings to carry the imposed load on a substantially vertical shaft is well known in the art. As imposed loads on the shaft are increased, it becomes necessary to construct large thrust bearings. Thus, housings in which the shaft is journeyed must be larger to house the shaft-thrust bearing assembly.
One solution to the problem of providing a relatively compact shaft-thrust bearing assembly is taught in the U.S. Pat. No. 4,033,647 granted July 5, 1977 to John A. Beavers. The Beavers patent teaches a tandem thrust bearing assembly in which a second thrust bearing carries load in excess of the load which can be carried by a first thrust bearing.